Why should Esau care? – Vayyishlach
Rashi turned a Biblical verse into a rhyme when he quoted Gen. 32:5, Im Lavan gar’ti (Jacob’s statement, “I dwelt with Laban”) into Im Lavan gar’ti v’taryag mitzvot shamar’ti (“I dwelt with Laban and observed the 613 commandments”).
Who was Jacob talking to? His brother Esau. But since Esau was far from orthodox observance, why should he care whether Jacob was froom or not?
It all depends on how un-froom Esau was. If later historical experience is an indicator, Esau was not totally devoid of mitzvah-observance.
He probably was what in our generation might be called “occasional orthodox”, not consistently or constantly observant of mitzvot, but once in a while finding himself keeping a mitzvah or two.
We find this phenomenon amongst countless people. They don’t daven regularly, but once in a while they say the Sh’ma.
They don’t keep kosher all the time, but sometimes they consciously buy and eat kosher food. They don’t observe Shabbat every week, but sometimes (or more often) they light Shabbat candles.
If that’s the sort of person Esau was, he could well be interested in knowing that Jacob wouldn’t let the negative Laban-influences prevent him from maintaining his Judaism.
One mitzvah in particular would impress Esau – the mitzvah of not hating your brother (Lev. 19:17).